batman-adv: don't compile the BLA switch if not requested

When the Bridge Loop Avoidance component is not compiled-in, its boolean switch
should be not compiled as well. This patch surrounds the switch with a proper
ifdef.

This behaviour was introduced by 9fd6b0615b5499b270d39a92b8790e206cf75833
("batman-adv: add bridge loop avoidance compile option")

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index ae9ac9a..030ce41 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -273,7 +273,9 @@
 	atomic_t bonding;		/* boolean */
 	atomic_t fragmentation;		/* boolean */
 	atomic_t ap_isolation;		/* boolean */
+#ifdef CONFIG_BATMAN_ADV_BLA
 	atomic_t bridge_loop_avoidance;	/* boolean */
+#endif
 #ifdef CONFIG_BATMAN_ADV_DAT
 	atomic_t distributed_arp_table;	/* boolean */
 #endif